Closure means for cans and the like containers



Feb. 8, 1938.

A. FORS YTH CLOSURE MEANS FOR CANS AND THE LIKE CONTAINERS Filed Nov. 9, 1934 3 Sheets-Sheet 1 2a ZZQ/ z 11 I .5; 27 as; 2.4 26 26 //V VE/VTOR iL/ RED TZRSYrH firrommsys Feb. 8, 1938.

CLOSURE MEANS FOR CANS AND THE LIKE CONTAINERS Filed Nov. 9, 1934 3 Sheets-Sheet 2 [Al vszvrox fla /mp FaRs YTH A. FORSYTH I 2,107,437

A. FOR SYTH 2,107,437 CLOSURE MEANS FOR CANS AND THE LIKE CONTAINERS Feb; s, 1938.

3 Sheets-Sheet 3 Patented Feb. 8, 1938 Lidia-123'? CLOSURE MEANs Fen oANs AND THE LIKE CONTAINERS Alfred Forsyth, London, England Application November 9, 1934, Serial No. 752,248 In Great Britain November 14, 1933 3 Claims.

The present invention relates to closure means for cans and the like containers of the kind having a circular opening and refers to closure means of the kind in which a flat-shaped lever lid is used. The invention also refers to an improved form of lever lid for effecting such can closure and also to processes for forming such an improved lever lid. According to the practice hitherto common in this art, a lever lid comprises in addition to the flat diaphragm 'an upstanding flange at or near its periphery which engages with a rim projecting inwardly from the mouth of the container, such a rim being usually provided with an outwardly facing annular groove to accommodate the leverin'g tool used for extracting the lid.

For reasons of manufacture the inwardly 'projecting rim at the mouth of the container is not formed integrally with the container itself but consists of a separate piece of material which is fixed into the mouth of the container during manufacture by soldering or equivalentmean's'. An object of the present invention is to produce a can closure employinga lever lid in which the said inwardly projecting rim at the mouth of the container is eliminated, thus considerably cheapening the manufacture of the container.

Another object of the invention is to provide an improved can closure of the kind referred to in which the clearance space between the lid diaphragm and the contents of the can or container is minimized. This is particularly desirable when the contents consists of a perishable liquid, whose preservation depends on the substantial exclusion of air.

These objects are accomplished according to the present invention'by the provision of a can or container in which the neck or part comprising the opening is substantially cylindrical internally next the said opening in combination with a fiatshaped lever lid having a set-up flange which includes a cylindrical part of greater diameter than the rest of the lid and adapted to engage tightly within the cylindrical part of the container neck.

More particularly the flange part of the lever lid is formed with an annular groove both above and below the cylindrical part engaging the neck of the container, the free edge of the lid terminating in an everted rim or bead for engagement with the levering tool. Such a lid is intended to be inserted with the diaphragm downwards and be pushed into the container sufficiently far to bring the diaphragm practically in contact with the contents of the can and in order to limit the degree to which the lid can be pushed in the mouth of the can, the latter preferably comprises an internally projecting rim formed integrally in the neck or mouth of the can by bulging the wall inwards below the cylindrical part next the opening. When the lid is pressed in the lower edge of the cylindrical part of the lid seats on the internally projecting rim of the can and prevents the lid-being pressed in too far.

In order to enable the lid to be extracted should it be inserted upside down either accidentally or intentionally, as may be required when the contents of the can is of such a nature that a clearance space is not undesirable, e. g. in the case of a non-perishable powder, the bottom of the flange part of the lid next the diaphragm is provided with an everted rim whereby a second annular groove or recess is formed between said everted rim and the lower end of the cylindrical part of the flange which engages with the interior of the mouth of the can.

The improved lever lid as above described is formed from a single blank of sheet material and a further object of the invention is the provision of improved pressing and rolling processes for forming said lever lid.

'The present invention consists in the features herein described either severally or any combination thereof and as defined in the appended claims, including such modifications as may occur to those skilled in the art within the scope of said claims.

In what follows an embodiment of the inven tion will be more particularly described with reference to the accompanying drawings which illustrate a cylindrical can having the improved closure means and two forms of construction of the improved lever lid. The following description also sets forth improved processes according to the invention for forming said lever lids.

In the drawings:

Fig. 1 shows the can with a leverlid in position, in central section through the axis of the can and lid. The showing of Fig. 1 also includes a cover plate secured on the can over the lid for the purposes of packing, storage, transport etc.

Figs. 2 to 7 show in a similar section to Fig. 1 one form of construction of the improved lever lid in successive stages of manufacture starting from Fig. 2 and finishing at Fig. 7.

Figs. 8 to 12 show in similar section to Fig. 1 a second form of construction of the improved lever lid in successive stages, of manufacture starting from Fig. 8.

Fig. 13 .shows in a similar view to Figs. 8 to 12 modification.

Fig. 14 is a similar view of a stage in the manufacture of a lid as shown in Figs. 8 to 12 having yet another minor modification.

Referring to Fig. l; the can comprises a cylindrical' body 20 and a basal diaphragm 2| secured to the bottom of the body 20 in a known manner. The opening of the can is at the top and next the opening is a part 22 the interior face of which is substantially cylindrical and extends right up to the opening. In order that this part may effectively grip the side of the lever lid it is preferably formed with a very slight taper converging in wardly. The free edge of the can is rolled over at 23 to form an everted bead. Immediately below the cylindrical part 22 is an inwardly projecting rim 24 formed by bulging inwards the material of the can and below this again is an outwardly projecting rim 25 formed in a similar manner. i

The lever lid comprises a diaphragm 26 and an upstanding flange part the outer'contour of which includes a cylindrical part 21 and above that an annular groove 28. The outer end of the flange part remote from thediaphragm is everted to form a rim or bead 29 beneath which a lever tool between whichand the lower edge 21a of the may be inserted for extracting the-lid. Next to the diaphragm 25 is formed an everted rim 39 cylindrical part is an annular gap or recess which serves for the introduction of the levering tool if the lid is inserted in the mouth of the can with the diaphragm upwards.

In Fig. l the lid is shown inserted with the diaphragm downwards and normally the con tents of the can will be filled up to the level of the groove formed by the outward bulging of the can wall at 25. In this case there is substantially no clearance between the level of the contents and the diaphragm of the lid. .The internal pro-' s 30 so that whichever way the lid is inserted the only part whichtouches the inside of themouth of the: can is the part 21 and in either case'a gap is left between ;the everted rim 29 or 30 and the inner surface of themouth 22' of the container, thus enabling a lever tool to be inserted for extracting the lid.

1 The depth at which the inwardly projecting rim 24 is situated is preferably such that the lever lid does not project above the mouth of the container whichever'way up it is inserted. This enables a fiat cover'plate- 3! to be placed over the lever'lid enclosing the latter, the free edge 32 of the cover plate being rolled over the bead 23 of .thecan mouth to secure the cover plate in position. In Fig. l the cover plate 3! is shown very slightly dished to give additional stiffness thereto. I r

Figs. 2 to '7 show successive stages in the formation of one form of construction of a lever lid suitable; for effecting a closure 'of a can as shown in Fig. l. The process of forming the lid consists of a seriesof six pressing and. Qlling operations as follows The first operation consists in cutting the blank from sheet material and drawing it to a cylindrical cup shaped form in one operation ina die press, the shape after this operation being shown in Fig. 2. Fig. 3 shows the shape after the next operation which consists in reducing the diameter of the flange next the diaphragm in a die press. The reduced diameter is shown at 33 and the original diameter at 34. In this way a shoulder is formed at 35.

The third operation consists in bulging out the lower portion of the upper part 34 of the flange wall as shown at 36 in Fig. 4. This operation is performed in a die press, using a bottom die in which a groove is formed to accommodate the bulge and a top die made in three parts viz.

a shanked lower steel pad whose diameter corresponds to 'the inside diameter of the part 33, an upper steel pad whose diameter corresponds to the inside diameter of part 34 and an intermediate rubber pad, the upper'and intermediate pads being threaded on the shank of the lower pad. The diameter of the rubber pad when unstrained is not greater than the inside diameter of the part 34 and when'after the top die has been entered into the blank the pressure is applied to the upper pad, the rubber pad is compressed and spreads laterally thus forcing the metal ofthe' blank intothe groove of 'the bottom die. In order that the blank now shaped as in Fig. 4 may be withdrawn from the bottom die the latter is split diametrically, the two halves being held together by any suitable clamping device.

The next operation (Fig. 5). is also performed in a die press and consists in heading to pro: duce the everted rim 3'! next the diaphragm. For this purpose a shouldered bottom die is used which is entered within the'blank, the shoulder engaging with the shoulder 35 at the lower end of the bulge 36; For this operationthe blank is reversed, the diaphragm 26 being now uppermost. The shoulder of the. die engaging with the shoulder 35 of the blank forms the pointof 7 support for the heading" operation and the length of the reduced diameter part of the die above the shoulder (below as seen in Fig. 5) is such as to give the necessary. increase of diam eter on the rim 3! when the top die is brought down and presses the diaphragm on to the faceof the bottom die.

the everted rim or bead at'the end of the lid remote from the diaphragm. This rolling :opera- 'tion is preferablyperformed with the lid held in'arotary chuck, the free edge being shaped between rollers held on stationary centres Finally; the'sixth operation consists in'rolling the flats on the bulge, 36 as shown at 36a in- Fig. 7, the lid being supported as in the previous operation on a rotary chuck and worked between This forms the H rollers with stationary centres. I cylindrical part for engagement with the interior. of the mouth of the can.

It will be seen that the finished lid comprises.

the basal diaphragm 26, everted rib 37, annular groove 33, cylindrical part 36a of greater diam,- eter than the rest of the lid, everted rim or head 38 at the outer edge and annular groove 39 between the everted bead 38 and cylindrical part 36a. Figs8 to 12 show successive stages inthe productionof a second form of construction of the improved lever lid. This is the form of construcheading operation, the

tion shown in Fig. 1 in place in the opening of the can. In this instance the first operation consists as before of cutting the blank from sheet material and drawing it into a cylindrical cup as shown in Fig. 8.

The second operation, the result of which is shown in Fig. 9, is likewise a pressing operation and consists in reducing the diameter of the part 40 next the diaphragm, this part being turned inside out in the process. For this purpose the cup shown in Fig. 8 is reversed and the free edge placed over a ring-shaped bottom die and the top die consists of two parts, a ring and a centre, of which the former cooperates with the ring-shaped bottom die to form the reversed bend 4|, the centre die passing through and pressing the diaphragm 26 downwards to form a new rightangle bend at 42. In this way a double walled flange is formed comprising an inner wall fill and an outer wall 43.

The third operation shown in Fig. 10 consists in reducing in a die press the diameter of the upper part of the outer wall 43 next the bend ll. The lower part of the outer wall 43 now forms the cylindrical part 21 for engagement with the inside of the mouth of the can and a shoulder is formed at 44.

The fourth operation (Fig. 11) is a heading operation for forming the everted rim 29 at the outer end of the flange part. For this purpose a ring bottom die is used which enters between the part 21 and the inner wall 48 and engages the shoulder 44 to form an abutment for the top die being a shouldered centre die which enters within the wall 40 and the heading at 29 being performed by the shoulder.

The fifth step of the process is a heading operation for forming the everted rim 30 next the diaphragm 36. For this purpose the lid is inverted and supported on the outer edge 4!, 29 and on a centre bottom die, the length of which is selected to give the required amount of spread at 313 when the top die is brought down. The lid may be passed out as finished in this state, being new in the same form as that illustrated in Fig. l and comprising in addition to the basal diaphragm 26 the everted rim 3B, cylindrical portion 21 terminating at 21a, the portion 21 being of greater diameter than the rest of the lid and adapted to engage in the mouth of the can, an annular groove 28 and an everted rim or bead 29 at the upper edge. It will be seen that the lower edge 21a of the cylindrical part 21 does not extend down as far as the everted rim 3!] so that an annular gap is left in which a lever may be inserted for extracting the lid if it is inserted diaphragm upwards.

In Figs. 1 and 12 the free edge 21a of the lid is left straight. As a sharp edge at this point may be considered undesirable a further operation as shown in Fig. 13 may be added. This consists in rolling in the free edge 21a to give a rounded lower end to the cylindrical part 21. This operation is preferably performed with the lid supported in a rotary chuck, the edge 21a being rolled in between rollers mounted on fixed centres. In order tobe able to get the rollers up to the work this operation (Fig. 13) must be performed before the operation of heading the diaphragm end shown in Fig. 12. It will be seen that in Fig. 13 the rim 3!) has not yet been formed.

The heading operation of Fig. 11 gives to the groove 38 a sloping wall between the rim or bead 29 and the shoulder 44 at the top of the cylindrical portion 21. As this is not very convenient for applying a lever a further operation of rolling in the wall at 28 to give a symmetrical groove 28a (Fig. 14) may also be added. This operation is performed similarly to the operation of Fig. 13 with a rotary chuck and stationary centred rollers and therefore if adopted must also be completed before the heading operation of Fig. 12.

' The improved can and lid of the present invention may be made from any suitable sheet material, preferably thin sheet metal, e. g. thin tin plate. The form illustrated in Figs. 2 to '7 is somewhat cheaper than that of Figs. 8 to 14 partly on account of the smaller amount of metal used but principally because it requires slightly less labour. This form of. construction is quite satisfactory for copper or brass and for ordinary (steel) tin plate of not less than 26 S. W. G. If, however, thin tin plate, e. g. of 30 S. W. G. is used it is found that a considerable amount of wasters result owing to the severe stretching in 1e bulging operation (Fig. 4).

For very thin materials such as 30 S. W. G. tin plate the second form of construction shown in Figs. 8 to 14 is particularly suitable, being free from the defect above mentioned in connection with the form shown in Figs. 2 to '7 when carried out in very thin material. It will be noticed that in the construction shown in Figs. 8 to 14 there is no operation in which the metal is severely stretched, all important changes in the diameter being in the direction of. reducing.

What I claim is:

1. For closing a container having a neck with smooth substantially cylindrical internal surface terminating in a circular mouth, a lever lid formed from a single piece of sheet material comprising a flat diaphragm part and an upstanding circumferential flange part including the following external features arranged in the order named: an outwardly projecting annular bead at the junction of the flange part and diaphragm part, an annular depression, an outwardly projecting annular bulge flattened to present a narrow cylindrical surface of greater diameter than any other part of the lid and thereby adapted to lodge tightly in the cylindrical neck of the container, a second annular depression and a terminal outwardly projecting bead.

2. For closing a container having a neck with smooth substantially cylindrical internal surface terminating in a circular mouth, a lever lid formed from a single piece of. sheet material comprising a flat diaphragm part and a single walled upstanding circumferential flange part including the following features arranged in the order named: an outwardly projecting annular head at the junction of the flange part and diaphragm part, an annular depression, an out wardly projecting annular bulge flattened topresent a narrow cylindrical surface of greater diameter than any other part of the lid and thereby adapted to lodge tightly in the cylindrical neck of the container, a second annular depression and a terminal outwardly projecting bead formed by curling over the free edge of the material outwardly.

3. For closing a container having a neck with smooth substantially cylindrical internal surface terminating in a circular mouth, a lever lid formed from a single piece of sheet material comprising a flat diaphragm part and a doublewalled upstanding circumferential flange part formed by folding over the material of the flange part outwardly on itself, the inner wall being in continuation of the diaphragm part and the outer wall in continuation of the inner wall; and wherein the inner wall is cylindrical and of smaller diameter than the diaphragm part, the circumference of which constitutes a projecting bead and the outer, wall presents an outwardly projecting bead at its junction with the inner wall and adjacent to' this a circumferential depression and next to this in succession an outwardly projecting annular bulge, which lies-mid Way between the two said projecting beads and is flattened to present a narrow cylindrical surface of greater diameter than either of said beads and is thereby adapted to lodge tightly in the cylindrical neck of. the container, the said bulge terminating at the free edge of the material and the gap between it and the bead at the circumference of the diaphragm constituting an annular recess.

ALFRED FORSYTH. 

